1. Learn to calculate ten minus eight plus seven on the basis of ten minus nine.

2. Use multiple methods to solve the problem

Cultivate the flexibility of students' thinking

3. In teaching

The initial infiltration is constant.

The more you reduce it.

The smaller the result.

Teaching focus:

Master the calculation of more than ten MINUS eight plus seven.

Teaching difficulties:

Calculate more than ten minus eight or seven by various methods.

Teaching process:

First, review.

1. Oral calculation

8+7= 8+5= 7+6= 7+4= 8+9= 7+7= 4+8= 6+7=

7+3= 8+8= 6+8= 7+9= 10-8= 10-7= 13-9= 17-9=

When students answer 13-9=

The teacher asked the students to talk about their ideas. Guide students to calculate this problem in different ways.

(Methods 1, 10-9= 1.

1+3=4; Method 2, 13-3= 10.

10-6=4; Method 3,9+(4) =13

13-9=4)

Second, the new lesson

1. Teaching 15-8

Show me fifteen frogs first.

Let the students count.

Then the teacher circled eight.

Q: At this time.

How much is left? How should I calculate it?

List formula: 15-8

Teacher: 15-8 What do you want to calculate? The teacher asked the two children at your table to speak first.

After the students have finished speaking.

The teacher asked them to compare their methods.

The teacher wrote the relevant methods on the blackboard in time.

(method 1, from the number of pictures; Method 2, 15-5= 10.

10-3=7; Method 3, 10-8=2.

2+5=7; Method 4,8+(7) =15

15-8=7)

Think and do.

Show me the kitten map first.

The teacher asked the students to sit at the same table and talk about what the pictures said. And the formula 13-8 is given.

Then ask the students to write their answers in the book in their favorite way.

Students complete the following exercises.

10-7= 14-8=

1 1-7= 15-8=

12-7= 16-8=

13-7= 17-8=

Recreate a chicken map.

The teacher asked the students to count.

And talk about the significance.

List the formula 13-7

At this time, the teacher asked the students to compare who was the cleverest and could work out 13-8.

After the students calculate,

The teacher asked the students to talk about the calculation method again.

And give a big red flower to the fast and right classmate.

Third, practice.

1, students complete the following exercises.

12-8= 13-7=

14-8= 15-7=

16-8= 17-7=

2. Relationship

13-6 7

14-7 13

12-8 8

15-7 4

Fourth, summary.

What did the teacher learn by asking the students today?

Organize knowledge in time.

And reveal the theme

The greatest happiness in life is to find that the person you love just loves you.